1. Field of the Invention
This invention relates to the production of a custom fit hearing instrument, ear mold, or other ear devices. Other ear devices for this purpose of this specification include musician's custom ear monitors, swim plugs, and custom fit ear pieces for personal communication devices such as cell phones, PDAs, digital audio playback devices for music or portable audio/video equipment and custom fit language translators.
2. Description of the Prior Art
When custom hearing instruments, ear molds, and other ear devices are manufactured presently, an impression is made of the client's auditory canal and pinna, and then shipped to a manufacturing facility. After completion, the product is shipped back to the facility from which the order was placed, usually with a one to three week span of time between the time the client placed the order and the delivery of the product to the client. Similar delays occur in the event of repair, loss, irreparable damage or need for modification of the hearing instrument, ear mold, or other ear device.
This method of doing business is less than optimal for several reasons.
The process of shipping an ear impression of the individual to the manufacturing facility often results in an inaccurate fit of the ear device due to the impression material (which is usually silicone and always malleable) being shaken and handled roughly in transit to the manufacturing facility, resulting in an inaccurate impression of the client's ear at the point of manufacture.
The one to three week delay in the delivery of the product order to the client represents a loss of value, and is very inconvenient to the client.
The cost of shipping the product and all of the considerable costs associated with the operation of a manufacturing facility are passed on to the end user of the product, creating a high price to the consumer.
A delay of more than a few days for the repair of a hearing instrument, ear mold, or other ear device is not only very inconvenient to the client, but also poses potential psychological, social, and safety risks to the client.
The loss of a hearing instrument, ear mold, or other ear device requires another impression to be taken of the client's auditory canal and pinna, and a repeat of the delay of the initial manufacturing process.
The prior art method described above has used rapid prototyping techniques at a central manufacturing facility. The three dimensional shape of a user's ear canal can be obtained by either scanning an impression of the ear with a white light scanner or a laser or other three dimensional digitizing device, or by probing the ear with a type of three dimensional probe. The scanning data is input into a computer. Three dimensional design or modeling software mathematically models the impression into the shape of the desired instrument, ear mold, or other ear device. Next, the mathematical model at the central facility is used to produce an actual hearing aid shell or other device for client application. Even using the new Rapid Prototyping techniques, the delay in sending impression of the ear canal or a mathematical model thereof to a distant location and receiving an actual device back to the retail office takes one to three weeks.
Rapid Manufacturing, also known as Rapid Prototyping, encompasses many different technologies, all having in common the principle of additive or subtractive creation of tangible three dimensional parts from data provided either by computer model or direct duplication.
A more complete listing of these technologies is available in Terry Wohlers' Wohlers Report 2003, but the major methods are described briefly in the following paragraphs.
Selective Laser Sintering is based upon the principle of applying laser energy to a powerdous material in order to fuse the material at the point of contact with the laser. The laser traces a cross sectional slice of the object to be created, causing a cross sectional layer of the object desired to be created, and after completion of the first layer, more powderous material is placed atop the fused layers, and the next cross sectional layer is created in the same manner. The process is repeated until the fully developed part is formed.
Stereolithography is similar to Selective Laser Sintering, but rather than fusing powder to form objects, this process calls for the solidifying of a photosensitive resin with laser energy. The laser traces the outline of the object, creating a solidified cross section of a part of the object to be created. After the section is created, the layer is lowered into the resin, and the step is repeated. The process continues until the desired object is completed.
Fused Deposition Modeling and other similar processes such as the Thermojet Technique include the steps of depositing a cross sectional layer of thermoplastic or photosensitive plastic material, solidifying the layer by means of either temperature regulation or light exposure, and then laying then next layer upon the first. The process is repeated until the desired object is produced.
Laminated Object Manufacturing is the process of cutting sheets of plastic or paper, with a laser, cutting tool, or heat source, cross sectional layer by cross sectional layer, and fusing the sheets together at the point at which they are sliced to produce the desired object.
The Drop on Powder Method includes the steps of depositing a binding agent upon a powderous material, and binding it together to create a cross sectional layer of the object to be produced. An additional layer of the powderous material is then laid upon the first layer, and that layer is bound together. The process is repeated until the desired object is formed.
The Visible Light Masking Method is a preferred method of producing ear shells, and calls for projecting an image of a cross section of the object or objects to be created upon a photo sensitive resin or liquid photopolymer. The visible light cures the layer at the point of projection, and then the solidified layer is separated from the point of projection, allowing more photosensitive resin to fill in where the cured layer was previously. Next the light is projected again, solidifying the second layer. The process is repeated until the desired object is formed.
3. Identification of Objects of the Invention
A primary object of this invention is to provide a method for solving the problem of insufficient customer service and inadequate value as a result of prior art methods of centralized manufacture of hearing instruments, ear molds, and other ear devices.
Another object of the invention is to provide hearing aid devices to customers in a timely manner reducing delay of one to three weeks to a matter of one and one-half days or less.